Pneumatic cannon



(No Model.)

D. M. MEFPORD. PNEUMATIC CANNON.

Patented Mar. 24, 1885.

Illfilllllllllllff N. PETERS. Plmto-Lilhographar. Washington, D.C,

provided with trunnions.

UNITED STATES PATENT OFFICE.

DAVID M. MEFFORD, OF TOLEDO, OHIO.

PNEUMATIC CANNON.

SPECIFICATION forming part of Letters Patent No. 314,298, dated March24, 1885.

Application filed March 17, 1884. (No model.)

To aZZ whom it may concern.-

Be it known that I, DAVID M. MEEEoRD, of Toledo, in the county of Lucasand State of Ohio, have invented certain Improvements in PneumaticGannon, of which the following is a specification.

Pneumatic guns, in order to possess the highest degree of efficiency,are necessarily made with barrels of greatlength, commonly of forty feetor more, the barrels being of relatively small diameter and usually ofthin material.

In consequence of these facts difficulty is eX- perienced in sustainingthe barrels and maintaining them in a straight and true condition, andalso in preventing their vibration when in use.

My invention consists in various details of construction, hereinafterdescribed and claimed, designed to impart stiffness to the structure,andto deliver the air with maximum effect against the projectile.

Referring to the accompanying drawings, Figure 1 represents asideelevation of my improved gun, Fig. 2, a longitudinal vertical section ofthe same; Fig. 3, atransverse section of the same on the line 00 .r,showing in their preferred form the clamps by which the barrel andmagazines are united. Fig. 4 is a cross-section on the liney y, ShOwingthe clamps Figs. 5 and 6 are views illustrating the combination of thebarrel with three and with four reservoir-tubes, respectively.

Referring to the drawings, A represents the barrel of the gun, which mayconsist under ordinary circumstances simply of a straight tube ofuniform diameter.

B B represent the two reservoir or magazine tubes, which are commonlymade of a cylindrical form and of a diameter considerably greater thanthat of the barrel.

by mechanics in similar cases.

working under high pressures the inner surfaces of the tubes may becoated with zinc, tin, or resinous or other matters adapted for thepurpose. At the rear end the barrel is connected with the two magazinesby means of a breech-section, O, which may be given any external form orconfiguration desired, which is provided in the forward side withopenings to receive the ends of the barrel and magazines, as shown.

The connection between the parts may be effected in any of the variousmodes practiced It is preferred, however, to thread the barreland'magazines externally and screw them firmly into correspondingopenings in the breech-piece, as shown. It is to be noted that thebreechpiece is made of large size in relation to the other parts, andadapted to retain a large quantity of air directly in rear of thebarrel, which has its bore continued through the breech end directlyinto the breech-section, as shown. This construction is advantageousinthat it permit-s a large volume of air to pass directly into the barrelwithout changing its direction or course of movement, whereby thepressure is rendered more fully available against the projectile duringthe exceedingly short time which is required for the delivery of theprojectilefrom the muzzle.

In practice it is found that the time required for the expulsion of theprojectile is so brief that if the air is compelled to change its thepresent invention having no special refer- 9 once thereto. In advance ofthis valve the barrel is provided with a movable breech-section orbreech -block, I, arranged to swing upon trnnnions, or otherwise movablein such manner that it may be opened laterally, so asto expose its endsand admit of the projectile I placed on a narrower carriage, and to beoperated with greater convenience, and also in that being introduced.

In order that the magazines may properly stiffen and strengthen thebarrel, and also prevent or counteract its strong tendency to vibrate, Iconnect the magazines and barrel firmly to each other at various pointsin their length by means of clamps K. The magazines being of tubularform possess great stiffness or rigidity in proportion to their weight,and being of considerable diameter they serve through the clamps toimpart great stiffness to the barrel. Inasmuch as the magazines areordinarily shorter than the barrel, and inasmuch as bodies of differentlengths vibrate under ordinary circumstances in different times, itfollows that the tendency of the barrel to vibrate will be counteractedby the vibrations which may occur on the part of the magazines.

The clamps K, which may be variously constructed, are preferablycomposed each of two castings, (1, adapted to span the magazines and theintermediate barrel, and especially on their inner surfaces to conformclosely thereto, and the two parts thus applied will be united by meansof bolts 1) or other fastening devices, by which they may be drawntightly into position upon the intermediate parts. The clamp at theinner or middle portion of the gun, or at the center of weight, may becast with trunnions c thereon, to give support to the gun and admit ofits being mounted in a carriage of ordinary construction.

When the gun is to be worked at very high pressure, or when for specialreasons a very large quantity of air is to be accumulated, I propose toemploy three magazines grouped about the barrel, as represented in Fig.3, or four arranged in the positions represented in Fig. 4.

I am aware that two short reservoir-tubes have been arranged at thesides of a gun-ban rel, and connected there with the two extremities;and this arrangement I do not claim, in asmuch as the union of the partsat their eX- tremities only was not designed to and will not in practiceprevent that tremulous motion or vibration which is established by thehandling and firing of the gun when made of the great lengths whichrecent experiments have demonstrated to be necessary.

It is manifest that when the barrel and magazine are connected at twopoints only they are perfectly free to vibrate independently, whereasthe use of three or more connections renders the independent vibrationimpossible. The vibration of the three members in unison, particularlywhen the parts are of difierent lengths, and therefore adapted tovibrate in different times, is practically impossible.

The arrangement of the magazines above and below the barrel, instead ofat its sides, is highly advantageous in that it reduces the width of thegun, and permits the same to be it permits the employment of thebreechblock opening in a lateral direction, which is in practicedesirable on account of the convenience of access thereto. It is furtheradvantageous in that the resistance of the upper magazine to tensilestrain, and the resistance of the lower magazine to longitudinalcompression, are rendered available to assist in supporting the barrel,which would not be the case were the magazines arranged at the sides ofthe barrel.

Having thus described my invention, what I claim is 1. In a pneumaticgun, a barrel having its bore continued directly through the rear end,two magazines located on opposite sides of the barrel, and abreech-section connecting the rear ends of the two reservoirs with the.open breech of the barrel.

2. In combination with the airreservoirs and the intermediategun-barrel, the metallic clamp connecting both reservoirs with thebarrel, and provided with trunnions or bearings.

3. In a pneumatic gun, a plurality of parallel elongated reservoirs, incombination with an intermediate barrel, a valve through which thebarrel communicates with the reservoirs, and a movable breech-block inadvance of the valve, to permit the introduction of the projectile.

- 4. In a pneumatic gun, a reservoir to hold compressed air or gas, abarrel fixed in rela tion thereto, a valve for opening and closingcommunication between the barrel and reservoir, and a breech block orsection opening laterally from the barrel in advance of the valve, topermit the insertion of the projectile.

5. In combination with the parallel reservoir, tubes B, and theintermediate barrel, A, the clamps K, each composed of two parts unitedby bolts, as described and shown.

'6. In combination with the breech section or reservoir, the twocylindrical reservoirs, and the intermediate barrel, all screwedthereto, the bore of the barrel being continued through its rear end andopening directly into the interior of the breeclrsection, as shown.

7. In a pneumatic gun, a barrel having its bore continued through thebreech end, iir

combination with an airretaining chamber of relatively great diameterarranged directly in rear of the barrel, and a plurality ofreservoir-chambers connected at their rear ends to the air-retainingchamber, and extended thence forward along the sides of the barrel,substantially as and for the purpose described.

DAVID M. MEFFORD.

Witnesses:

J OHN T. ARMS, WM. H. SHIPLEY.

